One known type of coin dispensing mechanism comprises a hopper containing a rotatable disc, the plane of the disc being inclined at an angle to the vertical. The disc carries pegs and as the disc rotates, coins in the hopper are captured between the pegs and are lifted in a position in which they rest against the face of the disc.
In the upper region of the disc there is a wiping arm which guides coins along the arm and into an exit duct for subsequent dispensing. FIGS. 1 and 2 show such a prior art device, with a hopper 10, disc 11, pegs 12, wiping arm 13 and exit duct 14.
With the prior art device, a problem occurs in that coins can get stuck between the back of the wiping arm 13 and the front face of the disc 11. The top face of the wiping arm is slightly sloped towards the disc to discourage coins falling off. However, in biasing a coin, an equal and opposite force is applied on to the wiping arm, causing it to move slightly away from the disc. During normal coin dispensing, this does not cause a problem, but if a coin is reluctant to move along the wiping face, for example because it is bent or otherwise damaged, the forces involved increase. The result can be that the coin can wedge into the gap between the disc and the back of the wiping arm. This jams the mechanism so badly that it usually has to be removed from the host machine, stripped down, re-built or re-set (usually with a new wiper arm) and re-fitted back into the host machine. The host machine is out of order for this lengthy duration.
Furthermore, the existing wiping arm arrangement is not self-adjusting and so relies heavily on the disc being stable during rotation. The arm cannot adjust for wear and so becomes more prone to jamming, as more and more coins are dispensed.